CROSS-REFERENCE TO RELATED APPLICATIONS
TECHNICAL FIELD
[0002] This invention relates to compounds that inhibit HIV proteolytic enzymes and processes
for preparing the compounds. The invention also relates to methods of using the disclosed
compounds for treating patients infected with HIV.
BACKGROUND AND SUMMARY
[0003] The AIDS epidemic is one of the most challenging problems in medicine in the 21st
century. A retrovirus designated human immunodeficiency virus (HIV) is the etiological
agent of the complex disease that includes progressive destruction of the immune system
(acquired immune deficiency syndrome; AIDS) and degeneration of the central and peripheral
nervous system. This virus was previously known as LAV, HTLV-III, or ARV. A common
feature of retrovirus replication is the extensive post-translational processing of
precursor polyproteins by a vitally encoded protease to generate mature vital proteins
required for virus assembly and function. Inhibition of this processing prevents the
production of normally infectious virus. It has been previously demonstrated that
genetic inactivation of the HIV encoded protease resulted in the production of immature,
non-infectious virus particles. These results indicate that inhibition of the HIV
protease represents a viable method for the treatment of AIDS and the prevention or
treatment of infection by HIV.
[0004] Among many strategies to combat this disease, highly active antiretroviral therapy
(HAART) with HIV protease inhibitors (PIs) in combination with reverse transcriptase
inhibitors (RTIs) continues to be the first line treatment for control of HIV infection.
This treatment regimen has definitely improved quality of life, enhanced HIV management,
and halted the progression of the disease. However, despite these impressive successes,
there remain many challenges to treating this devastating disease, including decreasing
both the toxicity of and complexity of these treatment regimens. In addition, there
is a growing population of patients that are developing multi-drug resistant strains
of HIV, and there is ample evidence that these strains can be further transmitted.
[0005] HAART has had a major impact on the AIDS epidemic in industrially advanced nations;
however, eradication of human immunodeficiency virus type 1 (HIV 1) appears to be
currently unachieved, in part due to the viral reservoirs remaining in blood and infected
tissues. The limitation of antiviral therapy of AIDS is also exacerbated by complicated
regimens, the development of drug-resistant HIV-1 variants, and a number of inherent
adverse effects. However, a number of challenges have nonetheless been encountered
in bringing about the optimal benefits of the currently available therapeutics of
AIDS and HIV-1 infection to individuals receiving HAART. They include (i) drug-related
toxicities; (ii) partial restoration of immunologic functions once individuals developed
AIDS; (iii) development of various cancers as a consequence of survival prolongation;
(iv) flame-up of inflammation in individuals receiving HAART or immune re-construction
syndrome (IRS); and (v) increased cost of antiviral therapy. Such limitations of HAART
are exacerbated by the development of drug-resistant HIV-1 variants.
[0006] Efforts to counter the development of resistance with new compounds have been recently
reported (
Ghosh AK, et al., Bioorg. Med. Chem. Lett. 1998;
Ghosh AK, et al., Farmaco 2001;
Ghosh AK, et al., ChemMedChem, 2006;
Yoshimura K, et al., J. Virol. 2002;
Koh Y, Nakata H, Maeda K., Antimicrob Agents Chemother, 2003). The FDA approved Darunavir on June 23, 2006; on October 21, 2008, FDA granted traditional
approval to Prezista (darunavir), co-administered with ritonavir and with other antiretroviral
agents, for the treatment of HIV-1 infection in treatment-experienced adult patients.
In addition to the traditional approval, a new dosing regimen for treatment-naïve
patients was approved (
Tie Y, et al., Proteins 2007;
Kovalevsky AY, et al., J. Med. Chem. 2006;
Ghosh AK, Chapsal BD, Weber IT, Mitsuya H., Acc. Chem. Res. 2008-;
Ghosh AK, et al., J. Med. Chem. 2006;
Ghosh AK, et al., J. Med. Chem. 2009;
Ghosh AK, Chen Y., Tetrahedron Lett., 1995). One of the PIs, darunavir (DRV), was first approved for HIV/AIDS patients harboring
drug-resistant HIV that do not respond to other antiretroviral drugs. Recently, DRV
has received full approval for all HIV/AIDS patients including children infected with
HIV-1. DRV incorporates a stereochemically defined fused
bis-tetrahydrofuran (
bis-THF) as the P2-ligand. Each of the documents cited herein is incorporated herein
by reference. Inhibition of HIV-1 protease has been documented as an effective strategy
for the treatment of HIV/AIDS.
[0007] Herein described are potent inhibitors of HIV protease, including against various
multidrug-resistant HIV-1 variants. In one embodiment, inhibitors described herein
show nearly a 10-fold inhibition improvement over Darunavir (DRV). In another embodiment,
inhibitors described herein also potently block protease dimerization by at least
a factor of 10-fold compared to DRV.
[0008] The invention described herein includes novel compounds and compositions for treating
patients in need of relief from HIV, AIDS, and AIDS-related diseases. In addition,
the invention described herein includes methods for treating HIV, AIDS, and AIDS-related
diseases using the compounds described herein as well as known compounds that heretofore
have not been used or described as being useful in the treatment of such diseases.
[0009] In an embodiment of the invention, a compound having the formula

or a pharmaceutically acceptable salt thereof; wherein
X1 is a bond and R6 is hydrogen;
X2 is S(O)2 and R4 is optionally substituted aryl;
R1 and R2 are each hydrogen;
R3 is sulfonyl, acyl, amino, alkyl, heteroalkyl, cycloalkyl, cycloheteroalkyl, aryl,
arylalkyl, heteroaryl, or heteroarylalkyl, each of which is optionally substituted;
R5 is arylalkyl, which is optionally substituted;
Z is

wherein * indicates the point of attachment; m is 0, 1, or 2;
W1 and W2 are in each instance independently selected from the group consisting of optionally
substituted alkylene, alkyleneoxy, alkyleneamino, alkylenethio, alkylenesulfoxyl,
and alkylenesulfonyl;
W3 is selected from the group consisting of amino, oxygen, alkylene, alkyleneoxy, alkyleneamino,
and heteroalkylene, wherein at least one of W1 or W2 is oxygen, and wherein when one of W1 or W2 is optionally substituted methylene, W3 is oxygen or alkyleneoxy, and wherein Z does not include a peroxide bond, a sulfenate
bond, or a sulfenamide bond;
W4 is optionally substituted ethylene or propylene; or
Z is

wherein * indicates the point of attachment; n is 1, 2, or 3;
W1 and W2 are in each instance independently selected from the group consisting of optionally
substituted methylene, oxygen, and amino;
W3 is selected from the group consisting of amino, oxygen, alkylene, and heteroalkylene,
wherein at least one of W1 or W2 is oxygen, and wherein when one of W1 or W2 is optionally substituted methylene, W3 is oxygen, and wherein Z does not include a peroxide bond, a sulfenate bond, or a
sulfenamide bond;
W4 is optionally substituted ethylene or propylene;
X3 is a bond; and
Y is hydrogen.
[0010] In another embodiment, a pharmaceutical composition comprising a therapeutically
effective amount of one or more of the compounds described herein for treating HIV
infection is described.
[0011] In another embodiment, compounds described are used in the treatment of HIV, AIDS,
and AIDS-related diseases. Also described herein is a method for treating a patient
in need of relieve of an HIV infection, the method comprising the step of administering
to a patient in need of relief from the HIV infection a therapeutically effective
amount of one or more compounds of any of the compounds or the compositions described
herein.
[0012] In another embodiment, described herein is the synthesis of a series of inhibitors
for HIV-1 protease that incorporate conformationally constrained and stereochemically
defined tris-tetrahydrofuran derivatives as the P2-ligands. These inhibitors have
shown marked enzyme-inhibitory and antiviral potency. A number of these inhibitors
are very potent against multi-drug resistant HIV-1 variants.
DETAILED DESCRIPTION
[0013] Embodiments of the invention are further described by the following enumerated clauses:
0. A compound having the formula

or a pharmaceutically acceptable salt thereof; wherein
X1 is a bond and R6 is hydrogen;
X2 is S(O)2 and R4 is optionally substituted aryl;
R1 and R2 are each hydrogen;
R3 is sulfonyl, acyl, amino, alkyl, heteroalkyl, cycloalkyl, cycloheteroalkyl, aryl,
arylalkyl, heteroaryl, or heteroarylalkyl, each of which is optionally substituted;
R5 is arylalkyl, which is optionally substituted;
Z is

wherein * indicates the point of attachment; m is 0, 1, or 2;
W1 and W2 are in each instance independently selected from the group consisting of optionally
substituted alkylene, alkyleneoxy, alkyleneamino, alkylenethio, alkylenesulfoxyl,
and alkylenesulfonyl;
W3 is selected from the group consisting of amino, oxygen, alkylene, alkyleneoxy, alkyleneamino,
and heteroalkylene, wherein at least one of W1 or W2 is oxygen, and wherein when one of W1 or W2 is optionally substituted methylene, W3 is oxygen or alkyleneoxy, and wherein Z does not include a peroxide bond, a sulfenate
bond, or a sulfenamide bond;
W4 is optionally substituted ethylene or propylene; or
X3 is a bond; and
Y is hydrogen.
1. A compound having the formula

or a pharmaceutically acceptable salt thereof; wherein
X1 is a bond and R6 is hydrogen;
X2 is S(O)2 and R4 is optionally substituted aryl;
R1 and R2 are each hydrogen;
R3 is sulfonyl, acyl, amino, alkyl, heteroalkyl, cycloalkyl, cycloheteroalkyl, aryl,
arylalkyl, heteroaryl, or heteroarylalkyl, each of which is optionally substituted;
R5 is arylalkyl, which is optionally substituted;
Z is

wherein * indicates the point of attachment; n is 1, 2, or 3;
W1 and W2 are in each instance independently selected from the group consisting of optionally
substituted methylene, oxygen, and amino;
W3 is selected from the group consisting of amino, oxygen, alkylene, and heteroalkylene,
wherein at least one of W1 or W2 is oxygen, and wherein when one of W1 or W2 is optionally substituted methylene, W3 is oxygen, and wherein Z does not include a peroxide bond, a sulfenate bond, or a
sulfenamide bond;
W4 is optionally substituted ethylene or propylene;
X3 is a bond; and
Y is hydrogen. 2. The compound of clause 1 wherein Z is

wherein * indicates the point of attachment. 3. The compound of clause 1 or 2 wherein
Z is

wherein W2 is an oxygen; and * indicates the point of attachment. 4. The compound of any one
of the preceding clauses wherein n is 1 or 2. 5. The compound of any one of the preceding
clauses wherein n is 1. 6. The compound of any one of the preceding clauses wherein
W4 is ethylene. 7. The compound of any one of the preceding clauses wherein W1, W2, and W3 are oxygen. 8. The compound of any one of the preceding clauses wherein Z is

9. The compound of any one of the preceding clauses wherein R3 is iso-butyl. 10. The compound of any one of the preceding clauses wherein R3 is optionally substituted arylalkyl. 11. The compound of any one of the preceding
clauses wherein W2 is oxygen. 12. The compound of any one of the preceding clauses wherein W3 is oxygen. 13. The compound of any one of the preceding clauses wherein W2 and W3 are oxygen. 14. The compound of any one of the preceding clauses wherein each of
W1, W2, and W3 is oxygen. 15. The compound of any one of the preceding clauses wherein W1 is optionally substituted methylene. 16. A pharmaceutical composition comprising
a therapeutically effective amount of one or more compounds of any one of the preceding
clauses for treating HIV infection. 17. The composition of clause 16 further comprising
one or more carriers, diluents, or excipients, or a combination thereof. 18. A method
for treating a patient in need of relieve of an HIV infection, the method comprising
the step of administering to a patient in need of relief from the HIV infection a
therapeutically effective amount of one or more compounds of any one of clauses 1
to 15 or the composition of clause 16 or 17. 19. The compound of clause 0 or 1 wherein
Z is

[0014] In another embodiment, a compound having the formula
W1= W2=W3=O
W1= CH2, W2=W3=O
W1=O, W2=CH2, W3=O
W1=W2=O, W3=CH2
n1=n2=1, 2, 3
Y=OMe, CH2NH2, NH2, other hetero and heteroalkyl groups
R= CHMe2, alkyl, heteroalkyl
K=OH, NH2, NHMe, NHR, SO2
is described.
[0015] In another embodiment, a compound having the formula
W1=W2=W3=O
W1=CH2, W2=W3=O
W1=O, W2=CH2; W3=O
W1=W2=O, W3=CH2
n1=n2=1, 2, 3
Y=OMe, CH2NH2, NH2, other hetero and heteroalkyl groups
R= CHMe2, alkyl, heteroalkyl
K=OH, NH2, NHMe, NHR, SO2,
is described.
[0016] In another embodiment, a compound having the formula
X=Y=Z=CH2
X=O,NR Y=Z=CH2, where R=H, Me, SO2Me, COMe, CO2Me,
X=Y=CH2, Z=O, NR
X=Z=CH2, Y=O, NR
is described, where Ar=p-PhOMe, p-PhNH
2, p-Ph-CH
2OH, p,m-substituted aromatic, substituted benoxazole, benzoxazole, benzodioxane, benzodioxolane.
[0017] In another embodiment, a compound having the formula
X=Y=Z=CH2
X=O.NR Y=Z=CH2, where R=H, Me, SO2Me, COMe, CO2Me,
X=Y=CH2, Z=O, NR
X=Z=CH2, Y=O, NR
is described, where Ar=p-PhOMe, p-PhNH
2, p-PH-CH
2OH, p,m-substituted aromatic, substituted benoxazole, benzoxazole, benzodioxane, benzodioxolane.
[0018] In one illustrative example, the compounds described herein are prepared by a method
comprising one or more, or all, of the steps shown in the following scheme.

[0019] The compounds described herein may contain one or more chiral centers, or may otherwise
be capable of existing as multiple stereoisomers. It is to be understood that in one
embodiment, the compounds, and compositions, methods, uses, and medicaments that include
them may be optically pure, or may be any of a variety of stereoisomeric mixtures,
including racemic and other mixtures of enantiomers and other mixtures of diastereomers.
It is also to be understood that such mixtures of stereoisomers may include a single
stereochemical configuration at one or more chiral centers, while including mixtures
of stereochemical configuration at one or more other chiral centers.
[0020] Similarly, the compounds described herein may include geometric centers, such as
cis, trans, E, and Z double bonds. It is to be understood that in another embodiment,
the compounds, and compositions, methods, uses, and medicaments that include them
may be pure, or may be any of a variety of geometric isomer mixtures. It is also to
be understood that such mixtures of geometric isomers may include a single configuration
at one or more double bonds, while including mixtures of geometry at one or more other
double bonds.
[0021] It has been discovered herein that the X-ray structures of both DRV-bound and TMC-126-bound
HIV-1 protease complexes revealed extensive protein-ligand hydrogen bonding interactions
involving the backbone of HIV-1 protease throughout the active site. In particular,
it has also been observed herein that both oxygens of the P2-
bis-THF ligand are involved in hydrogen bonding with Asp-29 and Asp-30 backbone NHs.
In addition, the bicyclic ligand appears to fill in the hydrophobic pocket at the
S2-subsite. Without being bound by theory, it is believed that the P2-
bis-THF is responsible for the superior drug-resistance properties of DRV. Without being
bound by theory, it is believed herein that to counter drug resistance, the inhibitor
design strategies could focus on maximizing inhibitor interactions with the HIV-1
protease active site, particularly to promote extensive hydrogen bond interactions
with the protein backbone atoms. It has been discovered herein that enhancing backbone
binding leads to PIs that maintain full potency against a panel of multidrug-resistant
HIV-1 variants. Based upon examination of the protein-ligand X-ray structure of DRV-bound
HIV-1 protease, it has been found that the incorporation of another tetrahydrofuran
ring on the
bis-THF ligand may provide additional ligand-binding site interactions. Particularly,
it appears that ligand oxygens may be able to effectively maintain backbone hydrogen
bonding with Asp29 and Asp30 as well as fill in the hydrophobic pocket effectively.
Without being bound by theory, it is believed that these interactions may further
improve drug-resistance properties of the PIs.
[0022] Such oxatricyclic ligand could have a number of possible stereochemical motifs, including
a
syn-syn-syn (
SSS-type) and a
syn-anti-syn (
SAS-type) isomers. Though both are potent compounds, it is discovered herein that the
SAS-type ligand-based PIs have higher affinity, when compared to
SSS-isomer. That observation is supported by examination of X-ray structure-based preliminary
models suggesting that the
SAS-type ligand-based PIs make enhanced interactions in the S2-subsite when compared
to
SSS-isomer.
[0023] In another embodiment, novel oxatricyclic [3(
R), 3a
S, 4a
S, 7a
R, 8a
S] and [3(
R), 3a
S, 4a
R, 7a
S, 8a
S]-ligands were designed, synthesized, and incorporated into the (
R)-hydroxyethyl sulfonamide isostere. Illustratively, compound
33 exhibits remarkable enzyme inhibitory and antiviral potency. The antiviral activity
of
33 against a panel of highly PI-resistant clinical HIV-1 variants in vitro was measured.
It was found that
33 effectively suppressed all tested clinical HIV-1 variants that are highly resistant
to a number of currently available PIs.
[0024] Without being bound by theory, it is believed that successful antiviral drugs exert
their virus-specific effects by interacting with viral receptors, virally encoded
enzymes, viral structural components, viral genes, or their transcripts without disturbing
cellular metabolism or function. However, at present, it is believed that current
antiretroviral drugs and agents are unlikely to be completely specific for HIV-1 or
to be devoid of toxicity or side effects in the therapy of AIDS. Those issues are
of special note because patients with AIDS and its related diseases will have to receive
antiretroviral therapy for a long period of time, perhaps for the rest of their lives.
[0025] Without being bound by theory, it is also suggested that the compounds described
herein may exert their utility by the inhibition of proteases encoded by human immunodeficiency
virus (HIV), such as HIV-1. It is appreciated that the compounds described herein
may inhibit the homodimer form of the HIV-1 protease, or it may inhibit formation
of a functional enzyme, e.g. inhibit dimerization of the protein subunits. The compounds
or pharmaceutically acceptable salts thereof, are of value in the prevention of infection
by HIV, the treatment of infection by HIV and the treatment of the resulting acquired
immune deficiency syndrome (AIDS), either as compounds, pharmaceutically acceptable
salts, or pharmaceutical composition ingredients.
[0026] It is appreciated that the compounds described herein may be used alone or in combination
with other compounds useful for treating such diseases, including those compounds
that may operate by the same or different modes of action. Further, it is appreciated
that the compounds and compositions described herein may be administered alone or
with other compounds and compositions, such as other antivirals, immunomodulators,
antibiotics and vaccines.
[0027] As used herein, the term "alkyl" includes a chain of carbon atoms, which is optionally
branched. As used herein, the term "alkenyl" and "alkynyl" includes a chain of carbon
atoms, which is optionally branched, and includes at least one double bond or triple
bond, respectively. It is to be understood that alkynyl may also include one or more
double bonds. It is to be further understood that alkyl is advantageously of limited
length, including C
1-C
24, C
1-C
12, C1-C
8, C
1-C
6, and C
1-C
4. It is to be further understood that alkenyl and/or alkynyl may each be advantageously
of limited length, including C
2-C
24, C
2-C
12, C
2-C
8, C
2-C
6, and C
2-C
4. It is appreciated herein that shorter alkyl, alkenyl, and/or alkynyl groups may
add less lipophilicity to the compound and accordingly will have different pharmacokinetic
behavior.
[0028] As used herein, the term "cycloalkyl" includes a chain of carbon atoms, which is
optionally branched, where at least a portion of the chain in cyclic. It is to be
understood that cycloalkylalkyl is a subset of cycloalkyl. It is to be understood
that cycloalkyl may be polycyclic. Illustrative cycloalkyl include cyclopropyl, cyclopentyl,
cyclohexyl, 2-methylcyclopropyl, cyclopentyleth-2-yl and adamantyl. As used herein,
the term "cycloalkenyl" includes a chain of carbon atoms, which is optionally branched,
and includes at least one double bond, where at least a portion of the chain in cyclic.
It is to be understood that the one or more double bonds may be in the cyclic portion
of cycloalkenyl and/or the non-cyclic portion of cycloalkenyl. It is to be understood
that cycloalkenylalkyl and cycloalkylalkenyl are each subsets of cycloalkenyl. It
is to be understood that cycloalkyl may be polycyclic. Illustrative cycloalkenyl include
cyclopentenyl, cyclohexylethen-2-yl and cycloheptenylpropenyl. It is to be further
understood that chain forming cycloalkyl and/or cycloalkenyl is advantageously of
limited length, including C
3-C
24, C
3-C
12, C
3-C
8, C
3-C
6, and C
5-C
6. It is appreciated herein that shorter alkyl and/or alkenyl chains forming cycloalkyl
and/or cycloalkenyl, respectively, may add less lipophilicity to the compound and
accordingly will have different pharmacokinetic behavior. As used herein the term
"alkylene" refers to a divalent alkyl moiety.
[0029] As used herein, the term "heteroalkyl" includes a chain of atoms that includes both
carbon and at least one heteroatom, and is optionally branched. Illustrative heteroatoms
include nitrogen, oxygen, and sulfur. In certain variations, illustrative heteroatoms
also include phosphorus, and selenium. As used herein, the term "cycloheteroalkyl"
including heterocyclyl and heterocycle, includes a chain of atoms that includes both
carbon and at least one heteroatom, such as heteroalkyl, and is optionally branched,
where at least a portion of the chain is cyclic. Illustrative heteroatoms include
nitrogen, oxygen, and sulfur. In certain variations, illustrative heteroatoms also
include phosphorus, and selenium. Illustrative cycloheteroalkyl include tetrahydrofuryl,
pyrrolidinyl, tetrahydropyranyl, piperidinyl, morpholinyl, piperazinyl, homopiperazinyl
and quinuclidinyl. As used herein the term "heteroalkylene" refers to a divalent heteroalkyl
moiety.
[0030] As used herein, the term "aryl" includes monocyclic and polycyclic aromatic groups,
including aromatic carbocyclic and aromatic heterocyclic groups, each of which may
be optionally substituted. As used herein, the term "carbaryl" includes aromatic carbocyclic
groups, each of which may be optionally substituted. Illustrative aromatic carbocyclic
groups described herein include phenyl and naphthyl. As used herein, the term "heteroaryl"
includes aromatic heterocyclic groups, each of which may be optionally substituted.
Illustrative aromatic heterocyclic groups include pyridinyl, pyrimidinyl, pyrazinyl,
triazinyl, tetrazinyl, quinolinyl, quinazolinyl, quinoxalinyl, thienyl, pyrazolyl,
imidazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl,
triazolyl, benzimidazolyl, benzoxazolyl, benzthiazolyl, benzisoxazolyl and benzisothiazolyl.
[0031] As used herein, the term "amino" includes the group NH
2, alkylamino, and dialkylamino, where the two alkyl groups in dialkylamino may be
the same or different, i.e. alkylalkylamino. Illustratively, amino includes methylamino,
ethylamino, dimethylamino and methylethylamino. In addition, it is to be understood
that when amino modifies or is modified by another term, such as aminoalkyl, or acylamino,
the above variations of the term amino are included therein. Illustratively, aminoalkyl
includes H
2N-alkyl, methylaminoalkyl, ethylaminoalkyl, dimethylaminoalkyl and methylethylaminoalkyl.
Illustratively, acylamino includes acylmethylamino and acylethylamino.
[0032] As used herein, the term "amino and derivatives thereof" includes amino as described
herein, and alkylamino, alkenylamino, alkynylamino, heteroalkylamino, heteroalkenylamino,
heteroalkynylamino, cycloalkylamino, cycloalkenylamino, cycloheteroalkylamino, cycloheteroalkenylamino,
arylamino, arylalkylamino, arylalkenylamino, arylalkynylamino and acylamino, each
of which is optionally substituted. The term "amino derivative" also includes urea
and carbamate.
[0033] As used herein, the term "hydroxy and derivatives thereof" includes OH, and alkyloxy,
alkenyloxy, alkynyloxy, heteroalkyloxy, heteroalkenyloxy, heteroalkynyloxy, cycloalkyloxy,
cycloalkenyloxy, cycloheteroalkyloxy, cycloheteroalkenyloxy, aryloxy, arylalkyloxy,
arylalkenyloxy, arylalkynyloxy and acyloxy, each of which is optionally substituted.
The term "hydroxy derivative" also includes carbamate.
[0034] As used herein, the term "thio and derivatives thereof" includes SH, and alkylthio,
alkenylthio, alkynylthio, heteroalkylthio, heteroalkenylthio, heteroalkynylthio, cycloalkylthio,
cycloalkenylthio, cycloheteroalkylthio, cycloheteroalkenylthio, arylthio, arylalkylthio,
arylalkenylthio, arylalkynylthio and acylthio, each of which is optionally substituted.
The term "thio derivative" also includes thiocarbamate.
[0035] As used herein, the term "acyl" includes formyl, and alkylcarbonyl, alkenylcarbonyl,
alkynylcarbonyl, heteroalkylcarbonyl, heteroalkenylcarbonyl, heteroalkynylcarbonyl,
cycloalkylcarbonyl, cycloalkenylcarbonyl, cycloheteroalkylcarbonyl, cycloheteroalkenylcarbonyl,
arylcarbonyl, arylalkylcarbonyl, arylalkenylcarbonyl, arylalkynylcarbonyl and acylcarbonyl,
each of which is optionally substituted.
[0036] As used herein, the term "carboxylate and derivatives thereof" includes the group
CO
2H and salts thereof, and esters and amides thereof, and CN.
[0037] The term "optionally substituted" as used herein includes the replacement of hydrogen
atoms with other functional groups on the radical that is optionally substituted.
Such other functional groups illustratively include amino, hydroxyl, halo, thiol,
alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, nitro, sulfonic acids
and derivatives thereof and carboxylic acids and derivatives thereof. Illustratively,
any of amino, hydroxyl, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl,
and/or sulfonic acid is optionally substituted.
[0038] As used herein, the term "optionally substituted aryl" includes the replacement of
hydrogen atoms with other functional groups on the aryl that is optionally substituted.
Such other functional groups illustratively include amino, hydroxyl, halo, thiol,
alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl, nitro, sulfonic acids
and derivatives thereof and carboxylic acids and derivatives thereof. Illustratively,
any of amino, hydroxyl, thiol, alkyl, haloalkyl, heteroalkyl, aryl, arylalkyl, arylheteroalkyl,
and/or sulfonic acid is optionally substituted.
[0039] Illustrative substituents include a radical -(CH
2)
xZ
X, where x is an integer from 0-6 and Z
X is selected from halogen, hydroxy, alkanoyloxy, including C
1-C
6 alkanoyloxy, optionally substituted aroyloxy, alkyl, including C
1-C
6 alkyl, alkoxy, including C
2-C
6, alkoxy, cycloalkyl, including C
3-C
8 cycloalkyl, cycloalkoxy, including C
3-C
8 cycloalkoxy, alkenyl, including C
2-C
6 alkenyl, alkynyl, including C
2-C
6 alkynyl, haloalkyl, including C
1-C
6 haloalkyl, haloalkoxy, including C
1-C
6 haloalkoxy, halocycloalkyl, including C
3-C
8 halocycloalkyl, halocycloalkoxy, including C
3-C
8 halocycloalkoxy, amino, C
1-C
6 alkylamino, (C
1-C
6 alkyl)(C
1-C
6 alkyl)amino, alkylcarbonylamino, N-(C
1-C
6 alkyl)alkylcarbonylamino, aminoalkyl, C
1-C
6 alkylaminoalkyl, (C
1-C
6 alkyl)(C
1-C
6 alkyl)aminoalkyl, alkylcarbonylaminoalkyl, N-(C
1-C
6 alkyl)alkylcarbonylaminoalkyl, cyano, and nitro; or Z
X is selected from -CO
2R
4 and -CONR
5R
6, where R
4, R
5, and R
6 are each independently selected in each occurrence from hydrogen, C
1-C
6 alkyl, and aryl-C
1-C
6 alkyl.
[0040] The term "prodrug" as used herein generally refers to any compound that when administered
to a biological system generates a biologically active compound as a result of one
or more spontaneous chemical reaction(s), enzyme-catalyzed chemical reaction(s), and/or
metabolic chemical reaction(s), or a combination thereof. In vivo, the prodrug is
typically acted upon by an enzyme (such as esterases, amidases and phosphatases),
simple biological chemistry, or other process in vivo to liberate or regenerate the
more pharmacologically active drug. This activation may occur through the action of
an endogenous host enzyme or a non-endogenous enzyme that is administered to the host
preceding, following, or during administration of the prodrug. Additional details
of prodrug use are described in
U.S. Pat. No. 5,627,165; and
Pathalk et al., Enzymic protecting group techniques in organic synthesis, Stereosel.
Biocatal. 775-797 (2000). It is appreciated that the prodrug is advantageously converted to the original
drug as soon as the goal, such as targeted delivery, safety, stability, and the like
is achieved, followed by the subsequent rapid elimination of the released remains
of the group forming the prodrug.
[0041] Prodrugs may be prepared from the compounds described herein by attaching groups
that ultimately cleave in vivo to one or more functional groups present on the compound,
such as - OH-, -SH, -CO
2H, -NR
2. Illustrative prodrugs include carboxylate esters where the group is alkyl, aryl,
aralkyl, acyloxyalkyl, alkoxycarbonyloxyalkyl as well as esters of hydroxyl, thiol
and amines where the group attached is an acyl group, an alkoxycarbonyl, aminocarbonyl,
phosphate or sulfate. Illustrative esters, also referred to as active esters, include
to 1-indanyl, N-oxysuccinimide; acyloxyalkyl groups such as acetoxymethyl, pivaloyloxymethyl,
β-acetoxyethyl, β-pivaloyloxyethyl, 1-(cyclohexylcarbonyloxy)prop-1-yl and (1 - aminoethyl)carbonyloxymethyl;
alkoxycarbonyloxyalkyl groups, such as ethoxycarbonyloxymethyl, α-ethoxycarbonyloxyethyl
and β-ethoxycarbonyloxyethyl; dialkylaminoalkyl groups, including di-lower alkylamino
alkyl groups, such as dimethylaminomethyl, dimethylaminoethyl, diethylaminomethyl
and diethylaminoethyl; 2-(alkoxycarbonyl)-2-alkenyl groups such as 2-(isobutoxycarbonyl)
pent-2-enyl and 2-(ethoxycarbonyl)but-2-enyl; and lactone groups such as phthalidyl
and dimethoxyphthalidyl.
[0042] Further illustrative prodrugs contain a chemical moiety, such as an amide or phosphorus
group functioning to increase solubility and/or stability of the compounds described
herein. Further illustrative prodrugs for amino groups include (C
3-C
20)alkanoyl; halo-(C
3-C
20)alkanoyl; (C
3-C
20)alkenoyl; (C
4-C
7)cycloalkanoyl; (C
3-C
6)- cycloalkyl(C
2-C
16)alkanoyl; optionally substituted aroyl, such as unsubstituted aroyl or aroyl substituted
by 1 to 3 substituents selected from the group consisting of halogen, cyano, trifluoromethanesulphonyloxy,
(C
1-C
3)alkyl and (C
1-C
3)alkoxy, each of which is optionally further substituted with one or more of 1 to
3 halogen atoms; optionally substituted aryl(C
2-C
16)alkanoyl, such as the aryl radical being unsubstituted or substituted by 1 to 3 substituents
selected from the group consisting of halogen, (C
1-C
3)alkyl and (C
1-C
3)alkoxy, each of which is optionally further substituted with 1 to 3 halogen atoms;
and optionally substituted heteroarylalkanoyl having one to three heteroatoms selected
from O, S and N in the heteroaryl moiety and 2 to 10 carbon atoms in the alkanoyl
moiety, such as the heteroaryl radical being unsubstituted or substituted by 1 to
3 substituents selected from the group consisting of halogen, cyano, trifluoromethanesulphonyloxy,
(C
1-C
3)alkyl, and (C
1-C
3)alkoxy, each of which is optionally further substituted with 1 to 3 halogen atoms.
The groups illustrated are exemplary, not exhaustive, and may be prepared by conventional
processes.
[0043] It is understood that the prodrugs themselves may not possess significant biological
activity, but instead undergo one or more spontaneous chemical reaction(s), enzyme-catalyzed
chemical reaction(s), and/or metabolic chemical reaction(s), or a combination thereof
after administration in vivo to produce the compound described herein that is biologically
active or is a precursor of the biologically active compound. However, it is appreciated
that in some cases, the prodrug is biologically active. It is also appreciated that
prodrugs may often serves to improve drug efficacy or safety through improved oral
bioavailability, pharmacodynamic half-life, and the like. Prodrugs also refer to derivatives
of the compounds described herein that include groups that simply mask undesirable
drug properties or improve drug delivery. For example, one or more compounds described
herein may exhibit an undesirable property that is advantageously blocked or minimized
may become pharmacological, pharmaceutical, or pharmacokinetic barriers in clinical
drug application, such as low oral drug absorption, lack of site specificity, chemical
instability, toxicity, and poor patient acceptance (bad taste, odor, pain at injection
site), and others. It is appreciated herein that a prodrug, or other strategy using
reversible derivatives, can be useful in the optimization of the clinical application
of a drug.
[0044] The term "therapeutically effective amount" as used herein, refers to that amount
of active compound or pharmaceutical agent that elicits the biological or medicinal
response in a tissue system, animal or human that is being sought by a researcher,
veterinarian, medical doctor or other clinician, which includes alleviation of the
symptoms of the disease or disorder being treated. In one aspect, the therapeutically
effective amount is that which may treat or alleviate the disease or symptoms of the
disease at a reasonable benefit/risk ratio applicable to any medical treatment. However,
it is to be understood that the total daily usage of the compounds and compositions
described herein may be decided by the attending physician within the scope of sound
medical judgment. The specific therapeutically-effective dose level for any particular
patient will depend upon a variety of factors, including the disorder being treated
and the severity of the disorder; activity of the specific compound employed; the
specific composition employed; the age, body weight, general health, gender and diet
of the patient: the time of administration, route of administration, and rate of excretion
of the specific compound employed; the duration of the treatment; drugs used in combination
or coincidentally with the specific compound employed; and like factors well known
to the researcher, veterinarian, medical doctor or other clinician of ordinary skill.
[0045] It is also appreciated that the therapeutically effective amount, whether referring
to monotherapy or combination therapy, is advantageously selected with reference to
any toxicity, or other undesirable side effect, that might occur during administration
of one or more of the compounds described herein. Further, it is appreciated that
the co-therapies described herein may allow for the administration of lower doses
of compounds that show such toxicity, or other undesirable side effect, where those
lower doses are below thresholds of toxicity or lower in the therapeutic window than
would otherwise be administered in the absence of a co-therapy.
[0046] As used herein, the term "composition" generally refers to any product comprising
the specified ingredients in the specified amounts, as well as any product which results,
directly or indirectly, from combinations of the specified ingredients in the specified
amounts. It is to be understood that the compositions described herein may be prepared
from isolated compounds described herein or from salts, solutions, hydrates, solvates,
and other forms of the compounds described herein. It is also to be understood that
the compositions may be prepared from various amorphous, non-amorphous, partially
crystalline, crystalline, and/or other morphological forms of the compounds described
herein. It is also to be understood that the compositions may be prepared from various
hydrates and/or solvates of the compounds described herein. Accordingly, such pharmaceutical
compositions that recite compounds described herein are to be understood to include
each of, or any combination of, the various morphological forms and/or solvate or
hydrate forms of the compounds described herein. Illustratively, compositions may
include one or more carriers, diluents, and/or excipients. The compounds described
herein, or compositions containing them, may be formulated in a therapeutically effective
amount in any conventional dosage forms appropriate for the methods described herein.
The compounds described herein, or compositions containing them, including such formulations,
may be administered by a wide variety of conventional routes for the methods described
herein, and in a wide variety of dosage formats, utilizing known procedures (see generally,
Remington: The Science and Practice of Pharmacy, (21
st ed,, 2005)).
[0047] It is to be understood that in the methods described herein, the individual components
of a co-administration or a combination can be administered by any suitable means,
contemporaneously, simultaneously, sequentially, separately or in a single pharmaceutical
formulation. Where the co-administered compounds or compositions are administered
in separate dosage forms, the number of dosages administered per day for each compound
may be the same or different. The compounds or compositions may be administered via
the same or different routes of administration. The compounds or compositions may
be administered according to simultaneous or alternating regimens, at the same or
different times during the course of the therapy, concurrently in divided or single
forms.
[0048] Illustrative routes of oral administration include tablets, capsules, elixirs and
syrups.
[0049] Illustrative routes for parenteral administration include intravenous, intraarterial,
intraperitoneal, epidural, intraurethral, intrastemal, intramuscular and subcutaneous,
as well as any other art recognized route of parenteral administration. Illustrative
means of parenteral administration include needle (including microneedle) injectors,
needle-free injectors and infusion techniques, as well as any other means of parenteral
administration recognized in the art. Parenteral formulations are typically aqueous
solutions which may contain excipients such as salts, carbohydrates and buffering
agents (preferably at a pH in the range from about 3 to about 9), but, for some applications,
they may be more suitably formulated as a sterile non-aqueous solution or as a dried
form to be used in conjunction with a suitable vehicle such as sterile, pyrogen-free
water. The preparation of parenteral formulations under sterile conditions, for example,
by lyophilization, may readily be accomplished using standard pharmaceutical techniques
well known to those skilled in the art. Parenteral administration of a compound is
illustratively performed in the form of saline solutions or with the compound incorporated
into liposomes. In cases where the compound in itself is not sufficiently soluble
to be dissolved, a solubilizer such as ethanol can be applied.
[0050] The dosage of each compound of the claimed combinations depends on several factors,
including: the administration method, the condition to be treated, the severity of
the condition, whether the condition is to be treated or prevented, and the age, weight,
and health of the person to be treated. Additionally, pharmacogenomic (the effect
of genotype on the pharmacokinetic, pharmacodynamic or efficacy profile of a therapeutic)
information about a particular patient may affect the dosage used.
[0051] In making the pharmaceutical compositions of the compounds described herein, a therapeutically
effective amount of one or more compounds in any of the various forms described herein
may be mixed with one or more excipients, diluted by one or more excipients, or enclosed
within such a carrier which can be in the form of a capsule, sachet, paper, or other
container. Excipients may serve as a diluent, and can be solid, semi-solid, or liquid
materials, which act as a vehicle, carrier or medium for the active ingredient. Thus,
the formulation compositions can be in the form of tablets, pills, powders, lozenges,
sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as
a solid or in a liquid medium), ointments, soft and hard gelatin capsules, suppositories,
sterile injectable solutions, and sterile packaged powders. The compositions may contain
anywhere from about 0.1% to about 99.9% active ingredients, depending upon the selected
dose and dosage form.
[0052] Some examples of suitable excipients include lactose, dextrose, sucrose, sorbitol,
mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin,
calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water,
syrup, and methyl cellulose. The formulations can additionally include: lubricating
agents such as talc, magnesium stearate, and mineral oil; wetting agents; emulsifying
and suspending agents; preserving agents such as methyl- and propyl-hydroxybenzoates;
sweetening agents; and flavoring agents. The compositions can be formulated so as
to provide quick, sustained or delayed release of the active ingredient after administration
to the patient by employing procedures known in the art. It is appreciated that the
carriers, diluents, and excipients used to prepare the compositions described herein
are advantageously GRAS (generally regarded as safe) compounds.
[0053] Examples of emulsifying agents are naturally occurring gums (e.g., gum acacia or
gum tragacanth) and naturally occurring phosphatides (e.g., soybean lecithin and sorbitan
monooleate derivatives). Examples of antioxidants are butylated hydroxy anisole (BHA),
ascorbic acid and derivatives thereof, tocopherol and derivatives thereof, butylated
hydroxy anisole, and cysteine. Examples of preservatives are parabens, such as methyl
or propyl p-hydroxybenzoate, and benzalkonium chloride. Examples of humectants are
glycerin, propylene glycol, sorbitol, and urea. Examples of penetration enhancers
are propylene glycol, DMSO, triethanolamine, N,N-dimethylacetamide, N,N-dimethylformamide,
2-pyrrolidone and derivatives thereof, tetrahydrofurfuryl alcohol, and AZONE. Examples
of chelating agents are sodium EDTA, citric acid, and phosphoric acid. Examples of
gel forming agents are CARBOPOL, cellulose derivatives, bentonite, alginates, gelatin
and polyvinylpyrrolidone. Examples of ointment bases are beeswax, paraffin, cetyl
palmitate, vegetable oils, sorbitan esters of fatty acids (Span), polyethylene glycols,
and condensation products between sorbitan esters of fatty acids and ethylene oxide
(e.g., polyoxyethylene sorbitan monooleate (TWEEN)).
METHODS AND EXAMPLES
Syn-Syn-Syn (SSS) tris-THF Alcohol
[0054]

[0055] Synthesis of Syn-Syn-Syn (SSS)-type tris-THF Alcohol The fused Syn-Syn-Syn (SSS)-type tris-tetrahydrofuran (tris-THF) ligands
8 and
10 were synthesized as outlined in Scheme 1. The (3
R, 3a
S, 6a
R)-3-hydroxyhexahydrofuro[2,3-
b]furan (bis-THF alcohol)
2 was prepared according to the known procedure. The bis-THF alcohol
2 was converted to the corresponding iodide
3 in 90% yield with triphenylphosphine and iodine, which undergoes
β-elimination to give the cyclic vinyl ether
4. Compound
4 is very volatile and was directly used for the next reaction in the presence of solvent.
Accordingly, cyclic vinyl ether
4 was treated with NIS and propargyl alcohol in CH
2Cl
2 at 0 °C to afford iodide
5 in 58% yield over three steps. Radical cyclization of
5 initiated by AIBN afforded the corresponding tris-THF alkene
6 which was cleaved by ozonolysis to afford the tris-THF ketone
7 in 68% yield over two steps. The syn-syn-syn configuration of
7 was confirmed by NOESY and X-ray crystal structure (FIG. 1). Reduction of ketone
7 with L-Selectride generated the alcohol
8 in 85% yield as a single isomer. Following the same procedure, the enantiomer 10
was prepared using
1 as the starting material.
Synthesis of Syn-Anti-Syn (SAS)-type tris-THF alcohol
[0056] Commercially available 2,3-dihydrofuran was treated with ethyl diazoacetate and anhydrous
CuSO
4 at reflux to provide the tetrahydrafuranyl cyclopropanyl ester
11 (4:1 dr) as shown in Scheme 2. LAH reduction of the resulting ester gave the corresponding
primary alcohol
12 in quantitative yield. Oxidation of primary alcohol
12 with IBX generated the corresponding aldehyde, which underwent an in-situ arrangement
to afford the racemic cyclic vinyl ether
4. With this route, racemate alkene
4 could be obtained from 2,3-dihydrofuran in three steps in 35% yield. In comparison,
it needs six steps to get the same alkene
4 described in Scheme 1.

[0057] The synthetic route for tris-THF with SAS ring fusion is depicted in Scheme 3. Alkene
4 was exposed to freshly prepared acetone-free DMDO in CH
2Cl
2 at -78 °C to afford the corresponding epoxide, which was opened by methanol/sodium
methoxide to provide the alcohol
13 in 96% yield. Addition of a catalytic amount (10%) of sodium methoxide is critical
for this reaction. The stereochemistry was confirmed by
1H-NMR coupling constant comparison and nOe analysis. Oxidation of the alcohol
13 with Dess-Martin reagent generated the corresponding ketone. L-Selectride reduction
of the ketone gave the 3-OH inverted alcohol
14 exclusively in 58% yield over two steps.

[0058] The inversion of the stereochemistry was easily confirmed by
1H-NMR and nOe analysis. Acylation of alcohol
14 and subsequent glycosylation with propargyl alcohol exchange promoted by TMSOTf provided
the corresponding acetals
15 and
16 in 4:1 ratio as an inseparable mixture. After removal of the acetyl protecting group,
the two diastereomers were readily separated by flash chromatography to provide the
corresponding alcohol. Conversion of the resulting alcohol to tricyclic alkene
18 was carried out in a two step sequence: 1) conversion of the hydroxyl group to the
thiocarbonyl derivative using 1,1'-thiocarbonyldiimidazole under neutral conditions
to the thiocarbonyl derivative
17 in 95% yield) radical cyclization with tri-
n-butyltin hydride in refluxing toluene initiated by AIBN to afford tricyclic alkene
18 in 75% yield. Cleavage of the double bond of the resulting alkene
18 with a stream of O
3 in CH
2Cl
2/CH
3OH at -78 °C generated the corresponding tricyclic ketone in 89% yield. L-Selectride
reduction of the resulting ketone gave the racemate SAS-type tris-THF alcohol (±)
-19 exclusively in 95% yield.

[0059] With the racemate SAS-type tris-THF alcohol (±)
-19 in hand, herein described are procedures to make enantiopure tris-THF alcohol (Scheme
3.7). Based on the strategy of preparing bis-THF alcohol, an enzyme kinetic resolution
was used to separate two enantiomers. Thus, the racemate compound (±)
-19 was resolved with immobilized lipase 30, vinyl acetate and DME for 36 h to afford
free alcohol (+)-
19 in 49% yield and acylated product
20 in 47% yield. Ester
20 was hydrolyzed with K
2CO
3 and methanol to get the other SAS-type tris-THF enantiomer (-)-
19 in 100% yield.
Synthesis THF-Cy-THF P2 Ligand 28 and 30
[0060] The synthesis of ligand
28 is depicted in Scheme 3.8. Enantiopure cyclopentenyl alcohol
22 was prepared according to a previously reported procedure. TBS protection and hydrolysis
of acetate
22 afforded the alcohol
23 in quantitative yield. It was converted to the corresponding bromo acetal utilizing
ethyl vinyl ether and NBS in CH
2Cl
2 followed by removal of TBS to give alcohol
24 in 85% yield over two steps. Treatment of alcohol
24 with NaH and propargyl bromide in the presence of TBAI gave the cyclization precursor
25 in 90% yield. The cascade cyclization using tri-
n-butyltin hydride in refluxing toluene initiated by AIBN generated the tricyclic alkene
26 in 79% yield. Acetal reduction with trifluoroboron diethyl etherate and triethylsilane
provided the alkene
27 in 76% yield. Cleavage of the double bond by ozonolysis at -78 °C followed by NaBH
4 reduction at -15 °C in a single operation afforded the P2 ligand
28 in 85% yield.
[0061] Treatment of alcohol
23 under Mitsunobu condition and the subsequent hydrolysis resulted in the corresponding
inverted alcohol
29 in 90% yield over 2 steps. Following the same procedure described earlier, ligand
30 was synthesized.

Synthesis of Inhibitor 31-36
[0062] The syntheses of inhibitors
31-36 are outlined in Scheme 6. The ligand alcohols were converted to the corresponding
p-nitrophenyl carbonate
37a-f utilizing
p-nitrophenyl chloroformate and N-methyl morpholine in various solvents. Commercially
available epoxide
38 was opened with isobutylamine in 2-propanol at 65 °C for 3 h. The crude product was
subjected to sulfonation to afford isostere
39 in quantitative yield according to a previously reported procedure. Treatment of
isostere
39 with trifluoroacetic acid followed by coupling of the amine with the corresponding
carbonate
37a-f to gives inhibitors
31-36.
Resistance Profiles for Inhibitors 33, 34
[0063]
Relative Antiviral activity of 33, and 34 against multi-drug resistant clinical isolates
in PHA-PBMs
Virus |
(33) |
(34) |
APV (Amprenavir) |
DRV (Darunavir) |
HIV-1ERS104pre (wild-type: X4) |
1 |
1 |
1 |
1 |
HIV-1MDR/B (X4) |
7 |
2 |
16 |
6 |
HIV-1MDR/C (X4) |
2 |
1 |
11 |
2 |
HIV-1MDR/G (X4) |
5 |
2 |
15 |
6 |
HIV-1MDR/TM (X4) |
4 |
2 |
15 |
6 |
HIV-1MDR/MM (R5) |
5 |
2 |
9 |
3 |
HIV-1MDR/JSL (R5) |
5 |
>2 |
13 |
5 |
[0064] The amino acid substitutions identified in the protease-encoding region of HIV-1
ERS104pre, HIV-1
B, HIV-1
C, HIV-1
G, HIV-1
TM, HIV-1
MM, HIV-1
JSL compared to the consensus type B sequence cited from the Los Alamos database include
L63P; L10I, K14R, L33I, M36I, M46I, F53I, K55R, I62V, L63P, A71V, G73S, V82A, L90M,
I93L; L10I, I15V, K20R, L24I, M36I, M46L, I54V, I62V, L63P, K70Q,V82A, L89M; L10I,
V11I, T12E, I15V, L19I, R41K, M46L, L63P, A71T, V82A, L90M; L10I, K14R, R41K, M46L,
I54V, L63P, A71V, V82A, L90M; I93L; L10I, K43T, M46L, I54V, L63P, A71V, V82A, L90M,
Q92K; and L10I, L24I, I33F, E35D, M36I, N37S, M46L, I54V, R57K, I62V, L63P, A71V,
G73S, V82A, respectively. HIV-1
ERS104pre served as a source of wild-type HIV-1. The IC
50 values were determined by using PHA-PBMs as target cells and the inhibition of p24
Gag protein production by each drug was used as an endpoint. The numbers in parentheses
represent the fold changes of IC
50 values for each isolate compared to the IC
50 values for wild-type HIV-1
ERS104pre. All assays were conducted in duplicate.